There are 10 titanic captains. I think Arlong will return as a vice captain beneath one of the 10 big BBP captains.
Why? As Vegapunk said, the world is sinking due to the ancient weapons. The sinking of the world would actually benefit Arlong’s agenda, as fishmen would reign supreme in a fully sunken planet.
Hence I think he will join Teach and possibly even help him acquire Shirahoshi. Teach will also probably support the sinking, as an ocean world would also benefit pirates. Also not to mention, the Gura gura no mi might be able to accelerate the sinking.
Ultimately I think he could be defeated by Aladdin in the final war. I can see Aladdin allying with the Barto Club and helping save Bartolomeo.
Why? As Vegapunk said, the world is sinking due to the ancient weapons. The sinking of the world would actually benefit Arlong’s agenda, as fishmen would reign supreme in a fully sunken planet.
Hence I think he will join Teach and possibly even help him acquire Shirahoshi. Teach will also probably support the sinking, as an ocean world would also benefit pirates. Also not to mention, the Gura gura no mi might be able to accelerate the sinking.
Ultimately I think he could be defeated by Aladdin in the final war. I can see Aladdin allying with the Barto Club and helping save Bartolomeo.